U.S. patent number 4,189,850 [Application Number 05/913,557] was granted by the patent office on 1980-02-26 for self-centering vegetable drying apparatus.
This patent grant is currently assigned to Frank L. Dieterich. Invention is credited to Stanton Abrams, Frank L. Dieterich.
United States Patent |
4,189,850 |
Dieterich , et al. |
February 26, 1980 |
Self-centering vegetable drying apparatus
Abstract
An apparatus for drying lettuce and other vegetables including a
basket in which wet lettuce is placed, a holder in which the basket
is removably received, and a motor for rotating the basket and
holder. When the basket is rotated to expel water through openings
in its sidewalls by centrifugal force, the sidewalls bend outwardly
to engage the holder and center the basket. The holding mechanism
is normally held against rotation by a brake. When the motor is
energized, current flows through the brake to release it. As a
safety feature, no power is applied to the motor and brake circuits
when the device is not in operation.
Inventors: |
Dieterich; Frank L. (Culver
City, CA), Abrams; Stanton (Los Angeles, CA) |
Assignee: |
Dieterich; Frank L. (Culver
City, CA)
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Family
ID: |
27121519 |
Appl.
No.: |
05/913,557 |
Filed: |
June 8, 1978 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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794556 |
May 6, 1977 |
4103432 |
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Current U.S.
Class: |
34/58; 210/380.1;
494/11; 494/12; 494/60; 494/84; 99/495; 99/511 |
Current CPC
Class: |
A23B
7/02 (20130101); A23N 12/086 (20130101); F26B
5/08 (20130101) |
Current International
Class: |
A23B
7/02 (20060101); A23N 12/08 (20060101); A23N
12/00 (20060101); F26B 5/00 (20060101); F26B
5/08 (20060101); F26B 017/30 () |
Field of
Search: |
;34/58,8 ;233/1C
;210/363,350,356,380,369,370,378,147,144,368 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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574551 |
|
Apr 1959 |
|
CA |
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8114 of |
|
1904 |
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GB |
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Primary Examiner: Wayner; William E.
Assistant Examiner: Joyce; Harold
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 794,556,
entitled VEGETABLE DRYING APPARATUS, filed on May 6, 1977, now U.S.
Pat. No. 4,103,432.
Claims
We claim:
1. An apparatus for drying vegetables comprising: a plastic basket
for containing the vegetables to be dried, said basket being of
circular cross section, having an open top end, a closed bottom end
and a sidewall that tapers toward said bottom end, said sidewall
being divided by slots into generally vertical elongated bands
capable of bending outwardly under centrifugal force, thereby
increasing the diameter of said basket and permitting water to
escape from said basket;
a rotatable holder for removably receiving said basket with a space
between said holder and said basket through which water expelled
from said basket under centrifugal force can escape, said holder
being dimensioned to be engaged by said bands upon outward bending
thereof;
motor means connected to said holder for rotating said holder and
said basket and thereby causing water to be expelled through said
openings in said sidewall by centrifugal force.
2. The apparatus of claim 1 wherein said holder is a generally
cylindrical metal drum.
3. The apparatus of claim 2 wherein said drum includes a radially
inwardly protruding ring positioned for engagement by said bands
upon outward bending of said bands.
4. The apparatus of claim 2 wherein said drum has openings therein
to permit the escape of water therefrom, and said apparatus further
comprises a splash shield surrounding said drum.
5. The apparatus of claim 1 wherein said holder is a generally
cylindrical metal drum having a bottom on which said basket rests
and an open top through which said basket is slidably received.
6. The apparatus of claim 1 further comprising brake means for
arresting rotation of said holder and said basket.
7. The apparatus of claim 6 further comprising a brake spring for
biasing said brake means toward a rotation arresting position and
electro-magnetic means for moving said brake means against the
force of said spring when energized.
8. The apparatus of claim 7 further comprising circuit means for
simultaneously energizing said motor means and brake means.
9. The apparatus of claim 1 further comprising means for centering
said basket in said holder prior to rotation thereof, including
radially inwardly projecting buttons carried by said holder for
engaging said basket.
10. The apparatus of claim 1 wherein said holder is rigid and
concentric with said basket.
11. The apparatus of claim 1 wherein said holder includes means for
engagement with said basket upon expansion of said basket.
12. The apparatus of claim 1 wherein said holder includes an
inwardly projecting ring for engagement by said basket.
13. An apparatus for drying vegetables comprising:
a plastic basket of circular cross-section for containing
vegetables to be dried, said basket having tapered but
approximately vertical sidewalls divided by elongated approximately
vertical slots into a plurality of approximately parallel outwardly
bendable bands;
a generally cylindrical drum having an open top end and dimensioned
to slidably receive said basket therein and to be engaged by said
bands upon outward bending thereof;
a plurality of buttons projecting inwardly from said drum near the
bottom thereof to position said basket;
motor means connected to said drum for rotating said drum and said
basket, thereby causing water to be driven from said basket and
causing said bands to bend outwardly under centrifugal force;
brake means for arresting rotation of said basket and said
drum;
a brake spring biasing said brake means toward a rotation arresting
position;
electro-magnetic means for moving said brake means against the
force of said spring when energized; and
means for simultaneously energizing said motor means and said brake
means.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for drying
vegetables, particularly lettuce.
In the course of preparing vegetables, it is frequently necessary
to dry them before they are refrigerated or served. Cut lettuce, in
particular, is customarily treated with ice water so that it will
be fresh and crisp when used later in salads and should be
partially dried so that salad dressing will not run off the leaves
too quickly, but some moisture should be retained to make the
lettuce more palatable.
In the past, lettuce has been dried by placing it in a perforated
basket that is shaken or rotated, either manually or by an electric
motor, the use of a motor being preferable, particularly for
commercial applications. Previously known vegetable dryers are
often difficult to clean, since they have numerous corners and
crevices that are not easily accessible. A thorough cleaning and
sanitizing usually requires that a skilled person disassemble the
device, using appropriate tools. Cleaning is, therefore, a
time-consuming process and may tend to be done with less frequency
than is desirable for food-handling equipment, particularly in the
case of a motorized dryer with a more complex structure. It is,
therefore, preferable to provide a dryer having a removable but
rotatable basket to facilitate cleaning. A problem arises, however,
in that a removable basket tends to shift off-center, producing
excessive vibration. Moreover, if the basket is plastic, which is
preferable from the point of view of cost and ease of sanitization,
and if it is not properly centered and supported, it tends to
deform under centrifugal force. This deformation tends to
exaggerate any out-of-balance condition and may induce excessive
vibration.
Motor-driven dryers are equipped with clutches for controlling the
rotation of the vegetable container. These clutch mechanisms are
sometimes of a type that can easily injure the hands of the
operator and present a particularly high risk of injury when the
device is being cleaned. Another dangerous aspect of previously
known vegetable dryers is the use of upstanding lugs that engage
and rotate a removable basket. If the dryer is turned on after the
basket is removed, the rotating lugs become a likely source of
injury.
The objective of the present invention is to provide a safe,
simple, convenient, easily sanitized and easy to operate apparatus
for drying lettuce and other vegetables that can be readily used in
restaurants and other food preparation facilities. Another
objective is to provide such an apparatus employing a removable
basket that is self-centering.
SUMMARY OF THE INVENTION
The present invention provides a vegetable-drying apparatus that
uniquely achieves the foregoing objectives. It includes a removable
basket for the vegetables having flexible sidewalls that bend
outwardly under centrifugal force as the basket is rotated. A
holder that slidably recieves the basket is engaged by the basket
sidewalls as they bend outwardly, thereby centering the basket
within the holder and preventing it from getting out of round or
escaping from the holder. Rotation of the basket to drive water out
through the sidewalls by centrifugal force is accomplished by a
motor connected to the holder.
In a preferred form of the invention, the basket is plastic and of
circular cross-section, the openings forming elongated slots
parallel to its axis of rotation. These slots define parallel
vertical bands on the sides of the basket that are capable of
bending outwardly in the required manner. The basket can be
provided with other openings, in addition to the slots, to permit
the water to escape more rapidly.
The holder may be in the form of a generally cylindrical,
open-topped, metal drum. Water escapes from the drum through drain
holes and side openings.
According to another aspect of the invention, a flywheel that
stabilizes the rotation of the holder and basket also cooperates
with a brake. A spring biases a brake shoe toward a flywheel
engaging position to arrest rotation of the basket, but is moved
electro-magnetically against the force of the spring toward a
disengaged position when the motor is energized. When the motor is
de-energized and the spring causes the brake to be engaged, there
is no current flowing in the brake or motor circuits. The danger of
an electric shock is, therefore, minimized. A timer can be included
to ensure that the preformance of the device is predictable and
repeatable.
Other features and advantages of the present invention will become
apparent from the following detailed description of a preferred
form thereof and the attached drawing which illustrates, by way of
example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cross-sectional view of a vegetable-drying
apparatus constructed in accordance with the present invention;
FIG. 1a is an enlarged, fragmentary view of a portion of the
apparatus indicated generally by the arrow A--A in FIG. 1;
FIG. 2 is a top view of the apparatus; and
FIG. 3 is a schematic representation of the brake, motor and
accompanying control circuitry.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The novel features of the present invention are embodied in an
exemplary vegetable-drying apparatus, illustrated in FIGS. 1
through 3 of the accompanying drawings. It includes a stand 10, a
drum-shaped holder 12 rotatably supported on the stand, a basket 14
received by the drum, a motor 16 for rotating the drum and basket,
and a brake 17 for arresting rotation of the drum and basket.
The basket 14 is molded of polypropylene plastic, which is easily
sanitized, well recognized as suitable for use in food-handling
equipment, and sufficiently flexible for present purposes. Being
approximately cylindrical, the basket 14 has a flat bottom 18, an
open top end 19 and is slightly tapered inwardly toward the bottom
after the manner of an inverted truncated cone for ease of
insertion in the drum 12, as shown in FIGS. 1 and 2 (the taper
being imperceptible in the drawings). In cross-section, the basket
is circular.
A plurality of evenly spaced substantially vertical elongated
openings or slots 20 extend up the sides of the basket 14
approximately parallel to its rotational axis, although at a small
angle to the axis due to the taper of the basket. The sides are
thus divided into relatively narrow, vertical, adjacent bands 21.
Additional openings in the sides of the basket 14 are formed by
three horizontal rows of smaller round perforations 22.
The drum 12, which is made of stainless steel, is also generally
cylindrical, with a flat bottom 23 and an open top 24, and slidably
receives the basket 14. An annular portion of the sidewalls of the
drum 12 forms a ring-shaped protrusion 25 that is radially offset
toward the center. The sides of the basket 14 come close to the
ring 25 but leave a small clearance.
Near the bottom of the drum 12 are a plurality of inwardly
projecting buttons 26 that contact the sides of the basket 14 when
it is inserted between them. Drain holes 27 are provided about the
circumference of the drum bottom 23 (FIG. 1a) and additional
openings 28 that allow water to escape under centrifugal force are
provided in three horizontal rows on the sides of the drum 12.
When the drum 12 is rotated, the bands 21 that form part of the
basket sidewalls flex outwardly under centrifugal force to engage
the ring 25. Since the bands 21 are all of equal flexibility, they
each bend an equal amount and, therefore, hold the basket 14 in the
center of the drum 12 and prevent it from getting out of round or
escaping from the drum during rotation. The bending of the bands 21
also causes the slots 20 to widen, particularly at their centers,
so that water carried by the lettuce can escape through the slots
as well as the perforations 22. Centrifugal force also causes water
to be expelled from the drum 12 through its drain holes 27 and
sidewall openings 28.
The function of the ring 25 is to hold the sides of the basket 14
at a fixed distance from the sides of the drum 12, allowing a
generally annular space between the basket and the drum to provide
a path for the escaping water. This feature of the invention can be
omitted to reduce manufacturing cost since a smaller but adequate
path will exist in the absence of the ring 25 due to the bowed
configuration of the basket 14 during rotation.
The stand 10 on which the drum 14 is supported has four
equally-spaced, elongated legs 32 at its corners that are connected
intermediate their ends by horizontal braces 34 and at the top by
an open frame 36. Suction cups 38 at the bottom ends of the legs 32
securely position the apparatus on any suitable flat surface. Four
integrally formed, slidably removable, polypropylene plastic panels
40 extend vertically between the legs 32 to form a shield 42 that
surrounds the drum 12. Water expelled from the drum 12 is thus
confined by the shield 42. The corners of the shield 42 where the
panels 40 meet are rounded for ease of sanitization and cleaning.
Alternatively, a cylindrical splash shield may be employed.
To position the shield 42, a downturned lip 44 extends about its
outer top edge and engages an upstanding flange 45 on top of the
frame 36. Since the shield 42 is received by the stand 10 without
any fastening device, it can be freely removed for cleaning without
using tools. The basket 14 can be removed from the drum 12 through
the large center opening of the frame 36 and becomes a convenient
container to store or serve the lettuce after processing.
A drip pan 46, made up of channel-shaped members connected
end-to-end to form the sides of a square, is positioned beneath the
lower edges of the shield 42 to collect the water that runs off,
and a drain spout 48 in the pan floor 50 can be connected to a
waste pipe or holding tank (not shown).
A disk-shaped horizontal turntable 52 is centrally located between
the legs 32 and rotatably mounted atop a vertical drive shaft 54.
Bearings 56 that position the shaft 54 are mounted on two
vertically spaced, horizontal cross-pieces 58 that extend between
the braces 34, or between opposite sides of the drip pan 46. The
bottom 23 of the drum 12 is permanently attached to the top of the
turntable 52 for rotation with the turntable.
The electric motor 16 is attached to one of the legs 32 and drives
the shaft 54 via two speed-reducing pulleys 66 and 68 and a V-belt
70, thereby supplying the power to rotate the basket 14, drum 12
and turntable 52. To stabilize the shaft 54 and eliminate
vibrations attributable to any unbalanced loading of the basket 14,
a flywheel 72 is attached to the lower end of the shaft 54 below
the cross-pieces 58. The weight of the flywheel 72 should be at
least equal to that of the basket 14, plus its contents.
Rotation of the basket 14 can be halted by the brake 17 which is
attached to one of the cross-pieces 58. The motor 16 and the brake
17 are controlled by a main switch 76 and an adjustable timer 78 in
series with the main switch is mounted on one of the legs 32. When
the main switch 78 is closed, the dryer is operated by simply
setting the timer 78 to the number of seconds of rotation
desired.
The brake 17, as shown schematically in FIG. 3, includes a brake
shoe 80 attached to the end of a pivotable arm 81 that is biased by
a brake spring 82 against the circumferential outer edge of the
flywheel 72. Frictional engagement of the brake shoe 80 with the
flywheel 72 prevents rotation. Accordingly, the flywheel 72
performs the double function of stabilizing the rotation of the
basket 14 and interacting with the brake shoe 80 to arrest rotation
of the basket. This use of one component to perform two functions
reduces the size, weight, cost and complexity of the dryer.
When a current is supplied through the main switch 76 and the timer
78 to a motor circuit 84, it is simultaneously supplied to a
parallel brake circuit 86, energizing a coil 88 which
electro-magnetically attracts the brake shoe 80 away from the
flywheel 72 to permit rotation. The inclusion of the timer 78 is
important since it permits the lettuce to be dried to a
predetermined extent and each successive lettuce batch is dried for
the same time period without the variations in drying time that
would result if the operator's judgement were relied upon in this
respect.
It should be noted that when the dryer is not in operation, no
current passes beyond the timer 78, even though the brake 17 is
applied, and the danger of electrical shock to persons loading or
unloading the device is greatly reduced or eliminated despite the
typically wet environment in which it is used. The main switch 76
can be opened to further reduce the danger of shock when, for
instance, the dryer is being cleaned, to prevent current from
passing to the timer 78.
The optimum speed of rotation and drying time can vary from a
matter of seconds to a few minutes, depending upon such factors as
the size of the basket 14, the wetness of the lettuce, and the
degree of drying desired. It should be noted that the term "drying"
as used herein does not necessarily imply removing all the water
from the lettuce since it is generally desirable to allow water to
remain making the lettuce more palatable and assisting in the
retention of salad dressing. By way of example, good results have
been achieved by rotation a twenty-inch diameter basket for 45
seconds at a speed of 600 r.p.m. The relatively short processing
time permits lettuce removed from cold storage to be dried before
its temperature rises objectionably.
It should be apparent from the foregoing that the invention
provides a safe, convenient, easily sanitized, and self-centering
apparatus for quickly drying lettuce and other vegetables. It
should be highly desirable for restaurant use. While a particular
form of the invention has been illustrated and described, it will
be apparent from the foregoing that various modifications can be
made without departing from the spirit and scope of the
invention.
* * * * *